At least seven people have been killed in a series of attacks in southern Israel near the resort town of Eilat.

The attacks hit a bus carrying off-duty soldiers back from their bases, a passenger car and a military patrol.

An Israeli military statement said a "large number" of assailants were working in multiple squads.

"Terrorists fired at a bus on its way to Eilat and fired an anti-tank rocket at another vehicle. At the same time, a military patrol hit an explosive device," it said.

A television station, Channel 10, later reported a fourth attack. There was no immediate confirmation from Israeli officials.

Reports from the first attack said a vehicle followed the bus, then two to three gunmen got out and opened fire with automatic weapons. The assailants fled with Israeli security forces in pursuit and a gun battle followed.

The second attack, which rescue services said was on a passenger car, happened close to the site of the earlier ambush.

Haaretz reported that in addition mortars were fired from the Egyptian side of the border.

Israel's military spokesman, Brigadier General Yoav Mordechai, said soldiers had been targeted by heavy weapons and explosive devices. He said civilians and soldiers were among the casualties.

TV footage showed the bus pulled over by a red rocky cliff. Windows and a door of the bus were shattered, and soldiers were patrolling the area on foot. Inside the bus, seats were stained with blood and luggage littered the aisle.

"We heard a shot and saw a window explode. I didn't really understand what was happening at first. After another shot there was chaos in the bus and everyone jumped on everyone else," passenger Idan Kaner told Channel 2 TV. He said the attack lasted three or four minutes until the bus was able to drive away.

An explosive device was later detonated under the vehicle of a military patrol called to the scene. Mordechai said the attackers might have fired mortars and an anti-tank missile at that vehicle,

The bus driver said he had seen Egyptian soldiers open fire, but Mordechai said he was not aware of any Egyptian military involvement. In Egypt, a senior security official denied that the attackers crossed into Israel from Sinai or that the vehicles were fired at from inside Egyptian territory.

Roads in the area and the local airport have been closed and the Israeli media is reporting a big manhunt is under way.

The ambush will fuel concerns that Egyptian security forces are losing control of the Sinai desert region bordering southern Israel following the removal of the longtime president, Hosni Mubarak, earlier this year.

According to Israeli security officials, the Sinai has long been a base for militant activity and the smuggling of arms to Palestinian groups in Gaza. The Egyptian military launched an operation earlier this week targeted at militant cells in the Sinai.

"The incident underscores the weak Egyptian hold on Sinai and the broadening of the activities of terrorists," the Israeli defence minister, Ehud Barak, said in a statement. "The real source of the terror is in Gaza and we will act against them with full force and determination."

A Hamas official, Ahmed Yousef, told the German DPA press agency the group welcomed the attacks but he did not believe it was behind them.